Price fraction
You are encouraged to solve this task according to the task description, using any language you may know.
A friend of mine runs a pharmacy. He has a specialised function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value. This value is regulated by a government department.
Task: Given a floating point value between 0.00 and 1.00, rescale according to the following table:
>= 0.00 < 0.06 := 0.10 >= 0.06 < 0.11 := 0.18 >= 0.11 < 0.16 := 0.26 >= 0.16 < 0.21 := 0.32 >= 0.21 < 0.26 := 0.38 >= 0.26 < 0.31 := 0.44 >= 0.31 < 0.36 := 0.50 >= 0.36 < 0.41 := 0.54 >= 0.41 < 0.46 := 0.58 >= 0.46 < 0.51 := 0.62 >= 0.51 < 0.56 := 0.66 >= 0.56 < 0.61 := 0.70 >= 0.61 < 0.66 := 0.74 >= 0.66 < 0.71 := 0.78 >= 0.71 < 0.76 := 0.82 >= 0.76 < 0.81 := 0.86 >= 0.81 < 0.86 := 0.90 >= 0.86 < 0.91 := 0.94 >= 0.91 < 0.96 := 0.98 >= 0.96 < 1.01 := 1.00
Ada
<lang Ada> type Price is delta 0.01 digits 3 range 0.0..1.0; function Scale (Value : Price) return Price is
X : constant array (1..19) of Price := ( 0.06, 0.11, 0.16, 0.21, 0.26, 0.31, 0.36, 0.41, 0.46, 0.51, 0.56, 0.61, 0.66, 0.71, 0.76, 0.81, 0.86, 0.91, 0.96 ); Y : constant array (1..20) of Price := ( 0.10, 0.18, 0.26, 0.32, 0.38, 0.44, 0.50, 0.54, 0.58, 0.62, 0.66, 0.70, 0.74, 0.78, 0.82, 0.86, 0.90, 0.94, 0.98, 1.0 ); Low : Natural := X'First; High : Natural := X'Last; Middle : Natural;
begin
loop Middle := (Low + High) / 2; if Value = X (Middle) then return Y (Middle + 1); elsif Value < X (Middle) then if Low = Middle then return Y (Low); end if; High := Middle - 1; else if High = Middle then return Y (High + 1); end if; Low := Middle + 1; end if; end loop;
end Scale; </lang> The solution uses fixed point type to prevent rounding and representation issues. With the above declarations a full coverage test: <lang Ada> with Ada.Text_IO; use Ada.Text_IO; procedure Test_Price_Fraction is
-- Put the declarations here Value : Price := Price'First;
begin
loop Put_Line (Price'Image (Value) & "->" & Price'Image (Scale (Value))); exit when Value = Price'Last; Value := Price'Succ (Value); end loop;
end Test_Price_Fraction; </lang> Sample output:
0.00-> 0.10 0.01-> 0.10 0.02-> 0.10 0.03-> 0.10 0.04-> 0.10 0.05-> 0.10 0.06-> 0.18 0.07-> 0.18 0.08-> 0.18 0.09-> 0.18 0.10-> 0.18 0.11-> 0.26 0.12-> 0.26 0.13-> 0.26 0.14-> 0.26 0.15-> 0.26 0.16-> 0.32 0.17-> 0.32 0.18-> 0.32 0.19-> 0.32 0.20-> 0.32 0.21-> 0.38 0.22-> 0.38 0.23-> 0.38 0.24-> 0.38 0.25-> 0.38 0.26-> 0.44 0.27-> 0.44 0.28-> 0.44 0.29-> 0.44 0.30-> 0.44 0.31-> 0.50 0.32-> 0.50 0.33-> 0.50 0.34-> 0.50 0.35-> 0.50 0.36-> 0.54 0.37-> 0.54 0.38-> 0.54 0.39-> 0.54 0.40-> 0.54 0.41-> 0.58 0.42-> 0.58 0.43-> 0.58 0.44-> 0.58 0.45-> 0.58 0.46-> 0.62 0.47-> 0.62 0.48-> 0.62 0.49-> 0.62 0.50-> 0.62 0.51-> 0.66 0.52-> 0.66 0.53-> 0.66 0.54-> 0.66 0.55-> 0.66 0.56-> 0.70 0.57-> 0.70 0.58-> 0.70 0.59-> 0.70 0.60-> 0.70 0.61-> 0.74 0.62-> 0.74 0.63-> 0.74 0.64-> 0.74 0.65-> 0.74 0.66-> 0.78 0.67-> 0.78 0.68-> 0.78 0.69-> 0.78 0.70-> 0.78 0.71-> 0.82 0.72-> 0.82 0.73-> 0.82 0.74-> 0.82 0.75-> 0.82 0.76-> 0.86 0.77-> 0.86 0.78-> 0.86 0.79-> 0.86 0.80-> 0.86 0.81-> 0.90 0.82-> 0.90 0.83-> 0.90 0.84-> 0.90 0.85-> 0.90 0.86-> 0.94 0.87-> 0.94 0.88-> 0.94 0.89-> 0.94 0.90-> 0.94 0.91-> 0.98 0.92-> 0.98 0.93-> 0.98 0.94-> 0.98 0.95-> 0.98 0.96-> 1.00 0.97-> 1.00 0.98-> 1.00 0.99-> 1.00 1.00-> 1.00
AutoHotkey
<lang AutoHotkey>; Submitted by MasterFocus --- http://tiny.cc/iTunis
Loop {
InputBox, OutputVar, Price Fraction Example, Insert the value to be rounded.`n* [ 0 < value < 1 ]`n* Press ESC or Cancel to exit, , 200, 150 If ErrorLevel Break MsgBox % "Input: " OutputVar "`nResult: " PriceFraction( OutputVar )
}
- -----------------------------------------
PriceFraction( p_Input ) {
If p_Input is not float ; returns 0 if input is not a float Return 0
If ( ( p_Input <= 0 ) OR ( p_Input >= 1 ) ) ; returns 0 is input is out of range Return 0
; declaring the table (arbitrary delimiters in use are '§' and '|') l_List := "0.06|0.10§0.11|0.18§0.16|0.26§0.21|0.32§0.26|0.38§0.31|0.44§0.36|0.50§0.41|0.54§0.46|0.58§0.51|0.62§0.56|0.66§0.61|0.70§0.66|0.74§0.71|0.78§0.76|0.82§0.81|0.86§0.86|0.90§0.91|0.94§0.96|0.98§1.01|1.00"
Loop, Parse, l_List, § ; retrieves each field (delimited by '§') { StringSplit, l_Array, A_LoopField, | ; splits current field (using delimiter '|') If ( p_Input <= l_Array1 ) Return l_Array2 ; returns the second value if input <= first value }
Return 0 ; returns 0, indicating failure (shouldn't be reached though)
}</lang>
ALGOL 68
- note: This specimen retains the original C coding style.
<lang algol68>main: (
# Just get a random price between 0 and 1 # # srand(time(NIL)); # REAL price := random; REAL tops := 0.06; REAL std val := 0.10;
# Conditionals are a little odd here "(price-0.001 < tops AND price+0.001 > tops)" is to check if they are equal. Stupid C floats, right? :) # WHILE ( price>tops OR (price-0.001 < tops AND price+0.001 > tops) ) AND tops<=1.01 DO tops+:=0.05;
IF std val < 0.26 THEN std val +:= 0.08 ELIF std val < 0.50 THEN std val +:= 0.06 ELSE std val +:= 0.04 FI;
IF std val > 0.98 THEN std val := 1.0 FI OD;
printf(($"Value : "z.2dl,"Converted to standard : "z.2dl$, price, std val))
)</lang> Sample Output:
Value : 0.38 Converted to standard : 0.54
AWK
<lang AWK> BEGIN {
O = ".06 .11 .16 .21 .26 .31 .36 .41 .46 .51 .56 .61 .66 .71 .76 .81 .86 .91 .96 1.01" N = ".10 .18 .26 .32 .38 .44 .50 .54 .58 .62 .66 .70 .74 .78 .82 .86 .90 .94 .98 1.00" fields = split(O,Oarr," ") # original values split(N,Narr," ") # replacement values for (i=-.01; i<=1.02; i+=.01) { # test printf("%5.2f = %4.2f\n",i,lookup(i)) }
} function lookup(n, i) {
if (n < 0 || n > 1.01) { return(0) # when input is out of range } for (i=1; i<=fields; i++) { # +10 is used because .11 returned .18 instead of .26 # under AWK95, GAWK, and MAWK; Thompson Automation's TAWK worked correctly if (n+10 < Oarr[i]+10) { return(Narr[i]) } }
} </lang>
BASIC
This could also be done by building an array, but I felt that this was simpler.
<lang qbasic>DECLARE FUNCTION PriceFraction! (price AS SINGLE)
RANDOMIZE TIMER DIM x AS SINGLE x = RND PRINT x, PriceFraction(x)
FUNCTION PriceFraction! (price AS SINGLE)
'returns price unchanged if invalid value SELECT CASE price CASE IS < 0! PriceFraction! = price CASE IS < .06 PriceFraction! = .1 CASE IS < .11 PriceFraction! = .18 CASE IS < .16 PriceFraction! = .26 CASE IS < .21 PriceFraction! = .32 CASE IS < .26 PriceFraction! = .38 CASE IS < .31 PriceFraction! = .44 CASE IS < .36 PriceFraction! = .5 CASE IS < .41 PriceFraction! = .54 CASE IS < .46 PriceFraction! = .58 CASE IS < .51 PriceFraction! = .62 CASE IS < .56 PriceFraction! = .66 CASE IS < .61 PriceFraction! = .7 CASE IS < .66 PriceFraction! = .74 CASE IS < .71 PriceFraction! = .78 CASE IS < .76 PriceFraction! = .82 CASE IS < .81 PriceFraction! = .86 CASE IS < .86 PriceFraction! = .9 CASE IS < .91 PriceFraction! = .94 CASE IS < .96 PriceFraction! = .98 CASE IS < 1.01 PriceFraction! = 1! CASE ELSE PriceFraction! = price END SELECT
END FUNCTION</lang>
Sample outputs (run 5 times):
.7388727 .82 .8593103 .9 .826687 .9 .3444635 .5 .0491907 .1
BBC BASIC
<lang bbcbasic> PRINT FNpricefraction(0.5)
END DEF FNpricefraction(p) IF p < 0.06 THEN = 0.10 IF p < 0.11 THEN = 0.18 IF p < 0.16 THEN = 0.26 IF p < 0.21 THEN = 0.32 IF p < 0.26 THEN = 0.38 IF p < 0.31 THEN = 0.44 IF p < 0.36 THEN = 0.50 IF p < 0.41 THEN = 0.54 IF p < 0.46 THEN = 0.58 IF p < 0.51 THEN = 0.62 IF p < 0.56 THEN = 0.66 IF p < 0.61 THEN = 0.70 IF p < 0.66 THEN = 0.74 IF p < 0.71 THEN = 0.78 IF p < 0.76 THEN = 0.82 IF p < 0.81 THEN = 0.86 IF p < 0.86 THEN = 0.90 IF p < 0.91 THEN = 0.94 IF p < 0.96 THEN = 0.98 = 1.00</lang>
Bracmat
Bracmat has no native support for floating point variables nor for the fixed point values in the conversion table. Instead this solution just applies a string comparison. <lang bracmat>( ( convert
= . ("0.06"."0.10") ("0.11"."0.18") ("0.16"."0.26") ("0.21"."0.32") ("0.26"."0.38") ("0.31"."0.44") ("0.36"."0.50") ("0.41"."0.54") ("0.46"."0.58") ("0.51"."0.62") ("0.56"."0.66") ("0.61"."0.70") ("0.66"."0.74") ("0.71"."0.78") ("0.76"."0.82") ("0.81"."0.86") ("0.86"."0.90") ("0.91"."0.94") ("0.96"."0.98") ("1.01"."1.00") : ? (>!arg.?arg) ? & !arg | "invalid input" )
& -1:?n & whl
' ( !n+1:?n:<103 & ( @(!n:? [<2)&str$("0.0" !n):?a | @(!n:? [<3)&str$("0." !n):?a | @(!n:?ones [-3 ?decimals) & str$(!ones "." !decimals):?a ) & out$(!a "-->" convert$!a) )
)</lang> Output:
0.00 --> 0.10 0.01 --> 0.10 0.02 --> 0.10 0.03 --> 0.10 0.04 --> 0.10 0.05 --> 0.10 0.06 --> 0.18 0.07 --> 0.18 0.08 --> 0.18 0.09 --> 0.18 0.10 --> 0.18 0.11 --> 0.26 0.12 --> 0.26 0.13 --> 0.26 0.14 --> 0.26 0.15 --> 0.26 0.16 --> 0.32 0.17 --> 0.32 ... 0.85 --> 0.90 0.86 --> 0.94 0.87 --> 0.94 0.88 --> 0.94 0.89 --> 0.94 0.90 --> 0.94 0.91 --> 0.98 0.92 --> 0.98 0.93 --> 0.98 0.94 --> 0.98 0.95 --> 0.98 0.96 --> 1.00 0.97 --> 1.00 0.98 --> 1.00 0.99 --> 1.00 1.00 --> 1.00 1.01 --> invalid input 1.02 --> invalid input
C
<lang c>#include<stdio.h>
double table[][2] = { {0.06, 0.10}, {0.11, 0.18}, {0.16, 0.26}, {0.21, 0.32}, {0.26, 0.38}, {0.31, 0.44}, {0.36, 0.50}, {0.41, 0.54}, {0.46, 0.58}, {0.51, 0.62}, {0.56, 0.66}, {0.61, 0.70}, {0.66, 0.74}, {0.71, 0.78}, {0.76, 0.82}, {0.81, 0.86}, {0.86, 0.90}, {0.91, 0.94}, {0.96, 0.98}, {1.01, 1.00}, {-1, 0}, /* guarding element */ };
double price_fix(double x) { int i; for (i = 0; table[i][0] > 0; i++) if (x < table[i][0]) return table[i][1];
abort(); /* what else to do? */ }
int main() { int i; for (i = 0; i <= 100; i++) printf("%.2f %.2f\n", i / 100., price_fix(i / 100.));
return 0; }</lang>
C#
<lang csharp>namespace ConsoleApplication1 {
class Program { static void Main(string[] args) { for (int x = 0; x < 10; x++) { Console.WriteLine("In: {0:0.00}, Out: {1:0.00}", ((double)x) / 10, SpecialRound(((double)x) / 10)); }
Console.WriteLine();
for (int x = 0; x < 10; x++) { Console.WriteLine("In: {0:0.00}, Out: {1:0.00}", ((double)x) / 10 + 0.05, SpecialRound(((double)x) / 10 + 0.05)); }
Console.WriteLine(); Console.WriteLine("In: {0:0.00}, Out: {1:0.00}", 1.01, SpecialRound(1.01));
Console.Read(); }
private static double SpecialRound(double inValue) { if (inValue > 1) return 1;
double[] Splitters = new double[] { 0.00 , 0.06 , 0.11 , 0.16 , 0.21 , 0.26 , 0.31 , 0.36 , 0.41 , 0.46 , 0.51 , 0.56 , 0.61 , 0.66 , 0.71 , 0.76 , 0.81 , 0.86 , 0.91 , 0.96 };
double[] replacements = new double[] { 0.10 , 0.18 , 0.26 , 0.32 , 0.38 , 0.44 , 0.50 , 0.54 , 0.58 , 0.62 , 0.66 , 0.70 , 0.74 , 0.78 , 0.82 , 0.86 , 0.90 , 0.94 , 0.98 , 1.00 };
for (int x = 0; x < Splitters.Length - 1; x++) { if (inValue >= Splitters[x] && inValue < Splitters[x + 1]) { return replacements[x]; } }
return inValue; } }
}</lang>
C++
<lang cpp>#include <iostream>
- include <cmath>
int main( ) {
double froms[ ] = { 0.00 , 0.06 , 0.11 , 0.16 , 0.21 , 0.26 , 0.31 , 0.36 , 0.41 , 0.46 , 0.51 , 0.56 , 0.61 , 0.66 , 0.71 , 0.76 , 0.81 , 0.86 , 0.91 , 0.96 } ; double tos[ ] = { 0.06 , 0.11 , 0.16 , 0.21 , 0.26 , 0.31 , 0.36 , 0.41 , 0.46 , 0.51 , 0.56 , 0.61 , 0.66 , 0.71 , 0.76 , 0.81 , 0.86 , 0.91 , 0.96 , 1.01 } ; double replacements [] = { 0.10 , 0.18 , 0.26 , 0.32 , 0.38 , 0.44 , 0.50 , 0.54 , 0.58 , 0.62 , 0.66 , 0.70 , 0.74 , 0.78 , 0.82 , 0.86 , 0.90 , 0.94 , 0.98 , 1.00 } ; double number = 0.1 ; std::cout << "Enter a fractional number between 0 and 1 ( 0 to end )!\n" ; std::cin >> number ; while ( number != 0 ) { if ( number < 0 || number > 1 ) {
std::cerr << "Error! Only positive values between 0 and 1 are allowed!\n" ; return 1 ;
} int n = 0 ; while ( ! ( number >= froms[ n ] && number < tos[ n ] ) )
n++ ;
std::cout << "-->" << replacements[ n ] << '\n' ; std::cout << "Enter a fractional number ( 0 to end )!\n" ; std::cin >> number ; } return 0 ;
} </lang>
Sample output: Enter a fractional number between 0 and 1 ( 0 to end )! 0.7 -->0.78 Enter a fractional number ( 0 to end )! 0.32 -->0.5 Enter a fractional number ( 0 to end )! 0.12 -->0.26 Enter a fractional number ( 0 to end )! 0
Clipper
<lang dbase>FUNCTION PriceFraction( npQuantDispensed )
LOCAL aPriceFraction := { {0,.06,.1},; {.06,.11,.18}, ; {.11,.16,.26}, ; {.16,.21,.32}, ; {.21,.26,.38}, ; {.26,.31,.44}, ; {.31,.36,.5}, ; {.36,.41,.54}, ; {.41,.46,.58}, ; {.46,.51,.62}, ; {.51,.56,.66}, ; {.56,.61,.7}, ; {.61,.66,.74}, ; {.66,.71,.78}, ; {.71,.76,.82}, ; {.76,.81,.86}, ; {.81,.86,.9}, ; {.86,.91,.94}, ; {.91,.96,.98} } LOCAL nResult LOCAL nScan IF npQuantDispensed = 0 nResult = 0 ELSEIF npQuantDispensed >= .96 nResult = 1 ELSE nScan := ASCAN( aPriceFraction, ; { |aItem| npQuantDispensed >= aItem[ 1 ] .AND.; npQuantDispensed < aItem[ 2 ] } ) nResult := aPriceFraction[ nScan ][ 3 ] END IF RETURN nResult</lang>
The function above crashes with an array access bound error if the value passed is negative. Also, the spec. indicates that 0.00 should be replaced with standard value 0.10, not 0. The following is a more concise solution:
<lang Clipper>Procedure Main()
Local i For i := -0.02 to 1.02 STEP 0.03 ? i, "->", PriceFraction(i), i+0.02, "->", PriceFraction(i+0.02) Next
Return
Static Function PriceFraction( nValue )
Local nResult Local n // Function is only defined for values 0 to 1.00 // Return NIL for anything else // Table of values {V1, V2} = {Threshhold, Standard value} #define TV_THRESHHOLD 1 #define TV_STD_VALUE 2 Local aTable := { {0, NIL },; {0.06, 0.10},; {0.11, 0.18},; {0.16, 0.26},; {0.21, 0.32},; {0.26, 0.38},; {0.31, 0.44},; {0.36, 0.50},; {0.41, 0.54},; {0.46, 0.58},; {0.51, 0.62},; {0.56, 0.66},; {0.61, 0.70},; {0.66, 0.74},; {0.71, 0.78},; {0.76, 0.82},; {0.81, 0.86},; {0.86, 0.90},; {0.91, 0.94},; {0.96, 0.98},; {1.01, 1.00} } n := AScan( aTable, {|x| nValue < x[TV_THRESHHOLD] }) If n > 0 nResult := aTable[n][TV_STD_VALUE] Else nResult := NIL Endif
Return nResult</lang>
Output:
-0.02 -> NIL 0.00 -> 0.10 0.01 -> 0.10 0.03 -> 0.10 0.04 -> 0.10 0.06 -> 0.18 0.07 -> 0.18 0.09 -> 0.18 0.10 -> 0.18 0.12 -> 0.26 0.13 -> 0.26 0.15 -> 0.26 0.16 -> 0.32 0.18 -> 0.32 0.19 -> 0.32 0.21 -> 0.38 0.22 -> 0.38 0.24 -> 0.38 0.25 -> 0.38 0.27 -> 0.44 0.28 -> 0.44 0.30 -> 0.44 0.31 -> 0.50 0.33 -> 0.50 0.34 -> 0.50 0.36 -> 0.54 0.37 -> 0.54 0.39 -> 0.54 0.40 -> 0.54 0.42 -> 0.58 0.43 -> 0.58 0.45 -> 0.58 0.46 -> 0.62 0.48 -> 0.62 0.49 -> 0.62 0.51 -> 0.66 0.52 -> 0.66 0.54 -> 0.66 0.55 -> 0.66 0.57 -> 0.70 0.58 -> 0.70 0.60 -> 0.70 0.61 -> 0.74 0.63 -> 0.74 0.64 -> 0.74 0.66 -> 0.78 0.67 -> 0.78 0.69 -> 0.78 0.70 -> 0.78 0.72 -> 0.82 0.73 -> 0.82 0.75 -> 0.82 0.76 -> 0.86 0.78 -> 0.86 0.79 -> 0.86 0.81 -> 0.90 0.82 -> 0.90 0.84 -> 0.90 0.85 -> 0.90 0.87 -> 0.94 0.88 -> 0.94 0.90 -> 0.94 0.91 -> 0.98 0.93 -> 0.98 0.94 -> 0.98 0.96 -> 1.00 0.97 -> 1.00 0.99 -> 1.00 1.00 -> 1.00 1.02 -> NIL
D
<lang d>import std.stdio;
double priceRounder(in double price) pure nothrow in {
assert(price >= 0 && price <= 1.0);
} body {
enum cin = [.06, .11, .16, .21, .26, .31, .36, .41, .46, .51, .56, .61, .66, .71, .76, .81, .86, .91, .96, 1.01]; enum cout = [.10, .18, .26, .32, .38, .44, .50, .54, .58, .62, .66, .70, .74, .78, .82, .86, .90, .94, .98, 1.00]; foreach (i, p; cin) if (p >= price) return cout[i]; assert(0);
}
void main() {
foreach (price; [0.7388727, 0.8593103, 0.826687, 0.3444635]) writeln(priceRounder(price));
}</lang>
- Output:
0.82 0.9 0.9 0.5
Erlang
<lang erlang>priceFraction(N) when N < 0 orelse N > 1 ->
erlang:error('Values must be between 0 and 1.');
priceFraction(N) when N < 0.06 -> 0.10; priceFraction(N) when N < 0.11 -> 0.18; priceFraction(N) when N < 0.16 -> 0.26; priceFraction(N) when N < 0.21 -> 0.32; priceFraction(N) when N < 0.26 -> 0.38; priceFraction(N) when N < 0.31 -> 0.44; priceFraction(N) when N < 0.36 -> 0.50; priceFraction(N) when N < 0.41 -> 0.54; priceFraction(N) when N < 0.46 -> 0.58; priceFraction(N) when N < 0.51 -> 0.62; priceFraction(N) when N < 0.56 -> 0.66; priceFraction(N) when N < 0.61 -> 0.70; priceFraction(N) when N < 0.66 -> 0.74; priceFraction(N) when N < 0.71 -> 0.78; priceFraction(N) when N < 0.76 -> 0.82; priceFraction(N) when N < 0.81 -> 0.86; priceFraction(N) when N < 0.86 -> 0.90; priceFraction(N) when N < 0.91 -> 0.94; priceFraction(N) when N < 0.96 -> 0.98; priceFraction(N) -> 1.00.</lang>
Euphoria
<lang euphoria>constant table = {
{0.06, 0.10}, {0.11, 0.18}, {0.16, 0.26}, {0.21, 0.32}, {0.26, 0.38}, {0.31, 0.44}, {0.36, 0.50}, {0.41, 0.54}, {0.46, 0.58}, {0.51, 0.62}, {0.56, 0.66}, {0.61, 0.70}, {0.66, 0.74}, {0.71, 0.78}, {0.76, 0.82}, {0.81, 0.86}, {0.86, 0.90}, {0.91, 0.94}, {0.96, 0.98}, {1.01, 1.00}
}
function price_fix(atom x)
for i = 1 to length(table) do if x < table[i][1] then return table[i][2] end if end for return -1
end function
for i = 0 to 99 do
printf(1, "%.2f %.2f\n", { i/100, price_fix(i/100) })
end for</lang>
Fantom
<lang fantom> class Defn // to hold the three numbers from a 'row' in the table {
Float low Float high Float value new make (Float low, Float high, Float value) { this.low = low this.high = high this.value = value }
}
class PriceConverter {
Defn[] defns := [,] new make (Str table) // process given table and store numbers from each row in a defn { table.split('\n').each |Str line| { data := line.split defns.add (Defn(Float.fromStr(data[1]), Float.fromStr(data[3]), Float.fromStr(data[5]))) } }
public Float convert (Float price) // convert by looking through list of defns { Float result := price defns.each |Defn defn| { if (price >= defn.low && price < defn.high) result = defn.value } return result }
}
class Main {
public static Void main () { table := ">= 0.00 < 0.06 := 0.10 >= 0.06 < 0.11 := 0.18 >= 0.11 < 0.16 := 0.26 >= 0.16 < 0.21 := 0.32 >= 0.21 < 0.26 := 0.38 >= 0.26 < 0.31 := 0.44 >= 0.31 < 0.36 := 0.50 >= 0.36 < 0.41 := 0.54 >= 0.41 < 0.46 := 0.58 >= 0.46 < 0.51 := 0.62 >= 0.51 < 0.56 := 0.66 >= 0.56 < 0.61 := 0.70 >= 0.61 < 0.66 := 0.74 >= 0.66 < 0.71 := 0.78 >= 0.71 < 0.76 := 0.82 >= 0.76 < 0.81 := 0.86 >= 0.81 < 0.86 := 0.90 >= 0.86 < 0.91 := 0.94 >= 0.91 < 0.96 := 0.98 >= 0.96 < 1.01 := 1.00" converter := PriceConverter (table) 10.times // simple test with random values { price := (0..100).random.toFloat / 100 echo ("$price -> ${converter.convert (price)}") } }
} </lang>
Forth
A floating-point version wouldn't be hard -- four words would change ( , @ @ cell+ -to- f, f@ f@ float+ ), EVALUATE would be replaced with a small word that forced a floating-point interpretation, and the return stack would not be used in ROUND -- but it would be strikingly unusual. See this page's discussion.
<lang forth>: as begin parse-word dup while evaluate , repeat 2drop ;
create bounds as 96 91 86 81 76 71 66 61 56 51 46 41 36 31 26 21 16 11 6 0 create official as 100 98 94 90 86 82 78 74 70 66 62 58 54 50 44 38 32 26 18 10
- official@ ( a-bounds -- +n )
\ (a+n) - a + b = (a+n) + (b - a) = (b+n) [ official bounds - ] literal + @ ;
- round ( n-cents -- n-cents' )
>r bounds begin dup @ r@ > while cell+ repeat r> drop official@ ;</lang>
Fortran
<lang fortran>program price_fraction
implicit none integer, parameter :: i_max = 10 integer :: i real, dimension (20), parameter :: in = & & (/0.00, 0.06, 0.11, 0.16, 0.21, 0.26, 0.31, 0.36, 0.41, 0.46, & & 0.51, 0.56, 0.61, 0.66, 0.71, 0.76, 0.81, 0.86, 0.91, 0.96/) real, dimension (20), parameter :: out = & & (/0.10, 0.18, 0.26, 0.32, 0.38, 0.44, 0.50, 0.54, 0.58, 0.62, & & 0.66, 0.70, 0.74, 0.78, 0.82, 0.86, 0.90, 0.94, 0.98, 1.00/) real :: r
do i = 1, i_max call random_number (r) write (*, '(f8.6, 1x, f4.2)') r, out (maxloc (in, r >= in)) end do
end program price_fraction</lang> Sample output: <lang>0.997560 1.00 0.566825 0.70 0.965915 1.00 0.747928 0.82 0.367391 0.54 0.480637 0.62 0.073754 0.18 0.005355 0.10 0.347081 0.50 0.342244 0.50</lang>
Go
<lang go>func pf(v float64) float64 {
switch { case v < .06: return .10 case v < .11: return .18 case v < .16: return .26 case v < .21: return .32 case v < .26: return .38 case v < .31: return .44 case v < .36: return .50 case v < .41: return .54 case v < .46: return .58 case v < .51: return .62 case v < .56: return .66 case v < .61: return .70 case v < .66: return .74 case v < .71: return .78 case v < .76: return .82 case v < .81: return .86 case v < .86: return .90 case v < .91: return .94 case v < .96: return .98 } return 1
}</lang>
Groovy
<lang groovy>def priceFraction(value) {
assert value >= 0.0 && value <= 1.0
def priceMappings = [(0.06): 0.10, (0.11): 0.18, (0.16): 0.26, (0.21): 0.32, (0.26): 0.38, (0.31): 0.44, (0.36): 0.50, (0.41): 0.54, (0.46): 0.58, (0.51): 0.62, (0.56): 0.66, (0.61): 0.70, (0.66): 0.74, (0.71): 0.78, (0.76): 0.82, (0.81): 0.86, (0.86): 0.90, (0.91): 0.94, (0.96): 0.98]
for (price in priceMappings.keySet()) { if (value < price) return priceMappings[price] } 1.00
}
for (def v = 0.00; v <= 1.00; v += 0.01) {
println "$v --> ${priceFraction(v)}"
}</lang> Output:
0.00 --> 0.10 0.01 --> 0.10 0.02 --> 0.10 0.03 --> 0.10 0.04 --> 0.10 0.05 --> 0.10 0.06 --> 0.18 0.07 --> 0.18 0.08 --> 0.18 0.09 --> 0.18 0.10 --> 0.18 0.11 --> 0.26 0.12 --> 0.26 0.13 --> 0.26 0.14 --> 0.26 0.15 --> 0.26 0.16 --> 0.32 0.17 --> 0.32 0.18 --> 0.32 0.19 --> 0.32 0.20 --> 0.32 0.21 --> 0.38 0.22 --> 0.38 0.23 --> 0.38 0.24 --> 0.38 0.25 --> 0.38 0.26 --> 0.44 0.27 --> 0.44 0.28 --> 0.44 0.29 --> 0.44 0.30 --> 0.44 0.31 --> 0.50 0.32 --> 0.50 0.33 --> 0.50 0.34 --> 0.50 0.35 --> 0.50 0.36 --> 0.54 0.37 --> 0.54 0.38 --> 0.54 0.39 --> 0.54 0.40 --> 0.54 0.41 --> 0.58 0.42 --> 0.58 0.43 --> 0.58 0.44 --> 0.58 0.45 --> 0.58 0.46 --> 0.62 0.47 --> 0.62 0.48 --> 0.62 0.49 --> 0.62 0.50 --> 0.62 0.51 --> 0.66 0.52 --> 0.66 0.53 --> 0.66 0.54 --> 0.66 0.55 --> 0.66 0.56 --> 0.70 0.57 --> 0.70 0.58 --> 0.70 0.59 --> 0.70 0.60 --> 0.70 0.61 --> 0.74 0.62 --> 0.74 0.63 --> 0.74 0.64 --> 0.74 0.65 --> 0.74 0.66 --> 0.78 0.67 --> 0.78 0.68 --> 0.78 0.69 --> 0.78 0.70 --> 0.78 0.71 --> 0.82 0.72 --> 0.82 0.73 --> 0.82 0.74 --> 0.82 0.75 --> 0.82 0.76 --> 0.86 0.77 --> 0.86 0.78 --> 0.86 0.79 --> 0.86 0.80 --> 0.86 0.81 --> 0.90 0.82 --> 0.90 0.83 --> 0.90 0.84 --> 0.90 0.85 --> 0.90 0.86 --> 0.94 0.87 --> 0.94 0.88 --> 0.94 0.89 --> 0.94 0.90 --> 0.94 0.91 --> 0.98 0.92 --> 0.98 0.93 --> 0.98 0.94 --> 0.98 0.95 --> 0.98 0.96 --> 1.00 0.97 --> 1.00 0.98 --> 1.00 0.99 --> 1.00 1.00 --> 1.00
Haskell
<lang haskell>price_fraction n
| n < 0 || n > 1 = error "Values must be between 0 and 1." | n < 0.06 = 0.10 | n < 0.11 = 0.18 | n < 0.16 = 0.26 | n < 0.21 = 0.32 | n < 0.26 = 0.38 | n < 0.31 = 0.44 | n < 0.36 = 0.50 | n < 0.41 = 0.54 | n < 0.46 = 0.58 | n < 0.51 = 0.62 | n < 0.56 = 0.66 | n < 0.61 = 0.70 | n < 0.66 = 0.74 | n < 0.71 = 0.78 | n < 0.76 = 0.82 | n < 0.81 = 0.86 | n < 0.86 = 0.90 | n < 0.91 = 0.94 | n < 0.96 = 0.98 | otherwise = 1.00</lang>
Alternative
:
<lang haskell>table = [
(0.06, 0.10), (0.11, 0.18), (0.16, 0.26), (0.21, 0.32), (0.26, 0.38), (0.31, 0.44), (0.36, 0.50), (0.41, 0.54), (0.46, 0.58), (0.51, 0.62), (0.56, 0.66), (0.61, 0.70), (0.66, 0.74), (0.71, 0.78), (0.76, 0.82), (0.81, 0.86), (0.86, 0.90), (0.91, 0.94), (0.96, 0.98), (1.01, 1.00), ]
price_fraction n
| n < 0 || n > 1 = error "Values must be between 0 and 1." | otherwise = snd $ head $ dropWhile ((<= n) . fst) table</lang>
HicEst
<lang HicEst>DIMENSION upperbound(20), rescaleTo(20), temp(20) upperbound = (.06,.11,.16,.21,.26,.31,.36,.41,.46,.51,.56,.61,.66,.71,.76,.81,.86,.91,.96,1.01) rescaleTo = (.10,.18,.26,.32,.38,.44,.50,.54,.58,.62,.66,.70,.74,.78,.82,.86,.90,.94,.98,1.00)
DO test = 1, 10
value = RAN(0.5, 0.5) temp = value > upperbound PriceFraction = rescaleTo( INDEX(temp, 0) ) WRITE(Format="F8.6, F6.2") value, PriceFraction
ENDDO</lang>
0.589230 0.70 0.017623 0.10 0.314343 0.50 0.553303 0.66 0.676283 0.78 0.016883 0.10 0.265656 0.44 0.460880 0.62 0.837450 0.90 0.228953 0.38
Icon and Unicon
<lang Icon> record Bounds(low,high,new)
- rescale given value according to a list of bounds
procedure rescale (i, bounds)
every bound := !bounds do if bound.low <= i < bound.high then return bound.new return fail # could not find i in bounds
end
procedure main ()
bounds := [ Bounds(0.00, 0.06, 0.10), Bounds(0.06, 0.11, 0.18), Bounds(0.11, 0.16, 0.26), Bounds(0.16, 0.21, 0.32), Bounds(0.21, 0.26, 0.38), Bounds(0.26, 0.31, 0.44), Bounds(0.31, 0.36, 0.50), Bounds(0.36, 0.41, 0.54), Bounds(0.41, 0.46, 0.58), Bounds(0.46, 0.51, 0.62), Bounds(0.51, 0.56, 0.66), Bounds(0.56, 0.61, 0.70), Bounds(0.61, 0.66, 0.74), Bounds(0.66, 0.71, 0.78), Bounds(0.71, 0.76, 0.82), Bounds(0.76, 0.81, 0.86), Bounds(0.81, 0.86, 0.90), Bounds(0.86, 0.91, 0.94), Bounds(0.91, 0.96, 0.98), Bounds(0.96, 1.01, 1.00) ]
# test the procedure every i := 0.00 to 1.00 by 0.1 do { write (i || " rescaled is " || rescale(i, bounds)) }
end </lang>
Output:
0.0 rescaled is 0.1 0.1 rescaled is 0.18 0.2 rescaled is 0.32 0.3 rescaled is 0.44 0.4 rescaled is 0.54 0.5 rescaled is 0.62 0.6 rescaled is 0.7 0.7 rescaled is 0.78 0.8 rescaled is 0.86 0.9 rescaled is 0.94 1.0 rescaled is 1.0
Inform 7
Inform doesn't have native floating-point support; this version uses fixed point numbers with two decimal places.
<lang inform7>Home is a room.
Price is a kind of value. 0.99 specifies a price.
Table of Price Standardization upper bound replacement 0.06 0.10 0.11 0.18 0.16 0.26 0.21 0.32 0.26 0.38 0.31 0.44 0.36 0.50 0.41 0.54 0.46 0.58 0.51 0.62 0.56 0.66 0.61 0.70 0.66 0.74 0.71 0.78 0.76 0.82 0.81 0.86 0.86 0.90 0.91 0.94 0.96 0.98 1.01 1.00
To decide which price is the standardized value of (P - price): repeat with N running from 1 to the number of rows in the Table of Price Standardization: choose row N in the Table of Price Standardization; if P is less than the upper bound entry, decide on the replacement entry.
When play begins: repeat with N running from 1 to 5: let P be a random price between 0.00 and 1.00; say "[P] -> [standardized value of P]."; end the story.</lang>
J
Solution: <lang j>le =: -0.96 0.91 0.86 0.81 0.76 0.71 0.66 0.61 0.56 0.51 0.46 0.41 0.36 0.31 0.26 0.21 0.16 0.11 0.06 0.0 out =: 1.00 0.98 0.94 0.90 0.86 0.82 0.78 0.74 0.70 0.66 0.62 0.58 0.54 0.50 0.44 0.38 0.32 0.26 0.18 0.1
priceFraction =: out {~ le I. -</lang>
Example: <lang j> priceFraction 0.34 0.070145 0.06 0.05 0.50214 0.56 1 0.99 0 0.5 0.18 0.18 0.1 0.62 0.7 1 1 0.1</lang>
This implementation performs a binary search on the boundary values, and then uses the resulting index to select from the result values.
To prevent J's binary search from doing the wrong thing for values equal to a boundary, both the boundary values and the search value are negated.
Java
<lang java>import java.util.Random;
public class Main { private static float priceFraction(float f) { if (0.00f <= f && f < 0.06f) return 0.10f; else if (f < 0.11f) return 0.18f; else if (f < 0.16f) return 0.26f; else if (f < 0.21f) return 0.32f; else if (f < 0.26f) return 0.38f; else if (f < 0.31f) return 0.44f; else if (f < 0.36f) return 0.50f; else if (f < 0.41f) return 0.54f; else if (f < 0.46f) return 0.58f; else if (f < 0.51f) return 0.62f; else if (f < 0.56f) return 0.66f; else if (f < 0.61f) return 0.70f; else if (f < 0.66f) return 0.74f; else if (f < 0.71f) return 0.78f; else if (f < 0.76f) return 0.82f; else if (f < 0.81f) return 0.86f; else if (f < 0.86f) return 0.90f; else if (f < 0.91f) return 0.94f; else if (f < 0.96f) return 0.98f; else if (f < 1.01f) return 1.00f; else throw new IllegalArgumentException(); }
public static void main(String[] args) { Random rnd = new Random(); for (int i = 0; i < 5; i++) { float f = rnd.nextFloat(); System.out.format("%8.6f -> %4.2f%n", f, priceFraction(f)); } } }</lang> Output:
0.149969 -> 0.26 0.310605 -> 0.50 0.616683 -> 0.74 0.194047 -> 0.32 0.724852 -> 0.82
JavaScript
In the task definition, the first step is 0.06, the rest are 0.05 so a re-factoring can subtract 0.01 from the value and divide by 0.05 to get the step.
Working with decimal numbers in JavaScript has issues, e.g. 0.06 - 0.01 = 0.049999999999999996 due to using IEEE 754 double precision numbers that can't accurately represent all decimals. So values are multiplied by 100 and integer arithmetic is used.
Note that multiplying a string by a number produces a number, the bitwise OR (|) truncates floating point numbers to integer, making it a concise replacement for Math.floor.
Passing a value outside the range 0 <= x < 1.01 will return undefined.
<lang javascript>function getScaleFactor(v) {
var values = ['0.10','0.18','0.26','0.32','0.38','0.44','0.50','0.54', '0.58','0.62','0.66','0.70','0.74','0.78','0.82','0.86', '0.90','0.94','0.98','1.00'];
return values[(v * 100 - 1) / 5 | 0];
}</lang>
K
Translation of the J solution:
<lang K> le:- 0.96 0.91 0.86 0.81 0.76 0.71 0.66 0.61 0.56 0.51 0.46 0.41 0.36 0.31 0.26 0.21 0.16 0.11 0.06 0.0 out: 1.00 0.98 0.94 0.90 0.86 0.82 0.78 0.74 0.70 0.66 0.62 0.58 0.54 0.50 0.44 0.38 0.32 0.26 0.18 0.1
pf:{out@_bin[le;-x]}' </lang> Output <lang K>
pf 0.6094701 0.5003597 0.8512954 0.08951883 0.6868076
0.7 0.62 0.9 0.18 0.78 </lang>
Liberty BASIC
<lang lb> dim DR(38) 'decimal range dim PF(38) 'corresponding price fraction range$="0.06 0.11 0.16 0.21 0.26 0.31 0.36 0.41 0.46 0.51 0.56 0.61 0.66 0.71 0.76 0.81 0.86 0.91 0.96 0.01" frac$="0.10 0.18 0.26 0.32 0.38 0.44 0.50 0.54 0.58 0.62 0.66 0.70 0.74 0.78 0.82 0.86 0.90 0.94 0.98 1.00" for i = 1 to 38
DR(i)=val(word$(range$,i)) PF(i)=val(word$(frac$,i))
next
for i = 0 to .99 step 0.03
print i;" -> ";PriceFraction(i)
next end
Function PriceFraction(n)
PriceFraction=n 'return original if outside test bounds for i = 1 to 38 if n<=DR(i) then PriceFraction=PF(i) exit for end if next end function
</lang>
Mathematica
<lang Mathematica>PriceFraction[x_]:=Piecewise[{{.1, 0 <= x < 0.06}, {.18, x < .11}, {.26,x < 0.16}, {.32, x < .21}, {.38, x < .26}, {.44, x < 0.31}, {.5, x < .36}, {.54, x < .41}, {.58, x < .46}, {.62, x < .51}, {.66, x < .56}, {.70, x < .61}, {.74, x < .66}, {.78, x < .71}, {.82, x < .76}, {.86, x < .81}, {.90, x < .86}, {.94, x < .91}, {.98, x < .96}}, 1]</lang>
MATLAB / Octave
<lang Matlab> function y = rescale(x)
L = [0,.06:.05:1.02]; V = [.1,.18,.26,.32,.38,.44,.50,.54,.58,.62,.66,.70,.74,.78,.82,.86,.9,.94,.98,1];
y = x; for k=1:numel(x); y(k) = V(sum(L<=x(k))); end; end;
t=0:0.001:1; plot(t,rescale(t)); </lang>
Mercury
<lang Mercury>:- module price.
- - interface.
- - import_module int.
- - type price == int.
- - func standard(price) = price.
- - implementation.
- - import_module require, list.
standard(P) = SP :-
require(P >= 0, "P must be positive"), Cents = P `mod` 100, P + adjust(Cents) = SP.
- - func adjust(int) = int.
adjust(Cents) = adjust(Cents, rules).
- - func adjust(int, list(price_rule)) = int.
adjust(_, []) = unexpected("price", "adjust/2", "exhausted rules"). adjust(N, [rule(Low, High, To)|T]) = R :-
( N >= Low, N < High -> To - N = R ; adjust(N, T) = R ).
- - type price_rule ---> rule(int, int, int).
- - func rules = list(price_rule).
rules = [rule(00, 06, 10),
rule(06, 11, 18), rule(11, 16, 26), rule(16, 21, 32), rule(21, 26, 38), rule(26, 31, 44), rule(31, 36, 50), rule(36, 41, 54), rule(41, 46, 58), rule(46, 51, 62), rule(51, 56, 66), rule(56, 61, 70), rule(61, 66, 74), rule(66, 71, 78), rule(71, 76, 82), rule(76, 81, 86), rule(81, 86, 90), rule(86, 91, 94), rule(91, 96, 98), rule(96, 101, 100)].</lang>
A build system might turn the text of the table into the definition of a hundred-element array of adjustments. In that case,
<lang Mercury>adjust(Cents) = array.lookup(price_table, Cents).</lang>
MUMPS
<lang MUMPS>PRICFRAC(X)
;Outputs a specified value dependent upon the input value ;The non-inclusive upper limits are encoded in the PFMAX string, and the values ;to convert to are encoded in the PFRES string. NEW PFMAX,PFRES,I,RESULT SET PFMAX=".06^.11^.16^.21^.26^.31^.36^.41^.46^.51^.56^.61^.66^.71^.76^.81^.86^.91^.96^1.01" SET PFRES=".10^.18^.26^.32^.38^.44^.50^.54^.58^.62^.66^.70^.74^.78^.82^.86^.90^.94^.98^1.00" Q:(X<0)!(X>1.01) "" FOR I=1:1:$LENGTH(PFMAX,"^") Q:($DATA(RESULT)'=0) SET:X<$P(PFMAX,"^",I) RESULT=$P(PFRES,"^",I) KILL PFMAX,PFRES,I QUIT RESULT</lang>
Output:
USER>W $$PRICFRAC^ROSETTA(.04) .10 USER>W $$PRICFRAC^ROSETTA(.06) .18 USER>W $$PRICFRAC^ROSETTA(.40) .54 USER>W $$PRICFRAC^ROSETTA(1.40) USER>W $$PRICFRAC^ROSETTA(.81) .90
OCaml
<lang ocaml>let price_fraction v =
if v < 0.0 || v >= 1.01 then invalid_arg "price_fraction"; let rec aux = function | (x,r)::tl -> if v < x then r else aux tl | [] -> assert false in aux [ 0.06, 0.10; 0.11, 0.18; 0.16, 0.26; 0.21, 0.32; 0.26, 0.38; 0.31, 0.44; 0.36, 0.50; 0.41, 0.54; 0.46, 0.58; 0.51, 0.62; 0.56, 0.66; 0.61, 0.70; 0.66, 0.74; 0.71, 0.78; 0.76, 0.82; 0.81, 0.86; 0.86, 0.90; 0.91, 0.94; 0.96, 0.98; 1.01, 1.00; ]</lang>
<lang ocaml>let () =
let ok_tests = [ (0.3793, 0.54); (0.4425, 0.58); (0.0746, 0.18); (0.6918, 0.78); (0.2993, 0.44); (0.5486, 0.66); (0.7848, 0.86); (0.9383, 0.98); (0.2292, 0.38); ] in Printf.printf " input res ok\n"; List.iter (fun (v,ok) -> let r = price_fraction v in Printf.printf " %6g %g %b\n" v r (r = ok); ) ok_tests;
- </lang>
Oz
Using a for-loop with return and a default value for values >= 1.01. For out-of-range input, a "failed value" is returned, i.e. a value that throws an exception when it is accessed.
<lang oz>fun {PriceFraction X}
OutOfRange = {Value.failed outOfRange(X)}
in
for Limit#Result in [0.00#OutOfRange 0.06#0.10 0.11#0.18 0.16#0.26 0.21#0.32 0.26#0.38 0.31#0.44 0.36#0.5 0.41#0.54 0.46#0.58 0.51#0.62 0.56#0.66 0.61#0.70 0.66#0.74 0.71#0.78 0.76#0.82 0.81#0.86 0.86#0.90 0.91#0.94 0.96#0.98 1.01#1.00 ] return:Return default:OutOfRange do if X < Limit then {Return Result} end end
end</lang>
PARI/GP
<lang parigp>priceLookup=[6,11,16,21,26,31,41,46,51,56,61,66,71,76,81,86,91,96,101]; priceReplace=[10,18,26,32,38,44,50,54,58,62,66,70,74,78,82,86,90,94,98,100]; pf(x)={
x*=100; for(i=1,19, if(x<priceLookup[i], return(priceReplace[i])) ); "nasal demons"
};</lang>
Pascal
<lang pascal>Program PriceFraction(output);
const
limit: array [1..20] of real = (0.06, 0.11, 0.16, 0.21, 0.26, 0.31, 0.36, 0.41, 0.46, 0.51, 0.56, 0.61, 0.66, 0.71, 0.76, 0.81, 0.86, 0.91, 0.96, 1.01); price: array [1..20] of real = (0.10, 0.18, 0.26, 0.32, 0.38, 0.44, 0.50, 0.54, 0.58, 0.62, 0.66, 0.70, 0.74, 0.78, 0.81, 0.86, 0.90, 0.94, 0.98, 1.00);
var
cost: real; i, j: integer;
begin
randomize; for i := 1 to 10 do begin cost := random; j := high(limit); while cost < limit[j] do dec(j); writeln (cost:6:4, ' -> ', price[j+1]:4:2); end;
end.</lang> Output:
% ./PriceFraction 0.8145 -> 0.90 0.6347 -> 0.74 0.0464 -> 0.10 0.9603 -> 1.00 0.3629 -> 0.54 0.5074 -> 0.62 0.4516 -> 0.58 0.2340 -> 0.38 0.4142 -> 0.58 0.8327 -> 0.90
Perl
<lang Perl>my @table = map [ /([\d\.]+)/g ], split "\n", <<'TBL'; >= 0.00 < 0.06 := 0.10 >= 0.06 < 0.11 := 0.18 >= 0.11 < 0.16 := 0.26 >= 0.16 < 0.21 := 0.32 >= 0.21 < 0.26 := 0.38 >= 0.26 < 0.31 := 0.44 >= 0.31 < 0.36 := 0.50 >= 0.36 < 0.41 := 0.54 >= 0.41 < 0.46 := 0.58 >= 0.46 < 0.51 := 0.62 >= 0.51 < 0.56 := 0.66 >= 0.56 < 0.61 := 0.70 >= 0.61 < 0.66 := 0.74 >= 0.66 < 0.71 := 0.78 >= 0.71 < 0.76 := 0.82 >= 0.76 < 0.81 := 0.86 >= 0.81 < 0.86 := 0.90 >= 0.86 < 0.91 := 0.94 >= 0.91 < 0.96 := 0.98 >= 0.96 < 1.01 := 1.00 TBL
sub convert {
my $money = shift; for (@table) { return $_->[2] if $_->[0] <= $money and $_->[1] > $money } die "Can't find currency conversion for $money. Counterfeit?"
}
- try it out
for (1 .. 10) {
my $m = rand(1); printf "%.3f -> %g\n", $m, convert($m);
} </lang>
Perl 6
<lang perl6>my $table = " >= 0.00 < 0.06 := 0.10 >= 0.06 < 0.11 := 0.18 >= 0.11 < 0.16 := 0.26 >= 0.16 < 0.21 := 0.32 >= 0.21 < 0.26 := 0.38 >= 0.26 < 0.31 := 0.44 >= 0.31 < 0.36 := 0.50 >= 0.36 < 0.41 := 0.54 >= 0.41 < 0.46 := 0.58 >= 0.46 < 0.51 := 0.62 >= 0.51 < 0.56 := 0.66 >= 0.56 < 0.61 := 0.70 >= 0.61 < 0.66 := 0.74 >= 0.66 < 0.71 := 0.78 >= 0.71 < 0.76 := 0.82 >= 0.76 < 0.81 := 0.86 >= 0.81 < 0.86 := 0.90 >= 0.86 < 0.91 := 0.94 >= 0.91 < 0.96 := 0.98 >= 0.96 < 1.01 := 1.00 ";
my $value = 0.44;
say price($value);
sub price($value) { for $table.lines -> $line { $line ~~ / '>=' \s+ (\S+) \s+ '<' \s+ (\S+) \s+ ':=' \s+ (\S+)/; return $2 if $0 <= $value < $1; } fail "Out of range"; }</lang> Perhaps a better approach is just to build an array of 101 entries. Memory is cheap, and array lookup is blazing fast, especially important if used in a loop as below. Moreover, in Perl 6 we don't have to worry about floating point misrepresentations of decimals because decimal fractions are stored as rationals.
<lang perl6>my @price = map *.value,
( 0 ..^ 6 X=> 0.10), ( 6 ..^ 11 X=> 0.18), (11 ..^ 16 X=> 0.26), (16 ..^ 21 X=> 0.32), (21 ..^ 26 X=> 0.38), (26 ..^ 31 X=> 0.44), (31 ..^ 36 X=> 0.50), (36 ..^ 41 X=> 0.54), (41 ..^ 46 X=> 0.58), (46 ..^ 51 X=> 0.62), (51 ..^ 56 X=> 0.66), (56 ..^ 61 X=> 0.70), (61 ..^ 66 X=> 0.74), (66 ..^ 71 X=> 0.78), (71 ..^ 76 X=> 0.82), (76 ..^ 81 X=> 0.86), (81 ..^ 86 X=> 0.90), (86 ..^ 91 X=> 0.94), (91 ..^ 96 X=> 0.98), (96 ..^101 X=> 1.00),
while prompt("value: ") -> $value {
say @price[ $value * 100 ] // note "Out of range";
}</lang>
Yet another approach is to use the conditional operator to encode the table. This allows each endpoint to be written once, avoiding duplication. <lang perl6>sub price_fraction ( Num $n where { $^n >= 0 and $^n <= 1 } ) {
( $n < 0.06 ) ?? 0.10 !! ( $n < 0.11 ) ?? 0.18 !! ( $n < 0.16 ) ?? 0.26 !! ( $n < 0.21 ) ?? 0.32 !! ( $n < 0.26 ) ?? 0.38 !! ( $n < 0.31 ) ?? 0.44 !! ( $n < 0.36 ) ?? 0.50 !! ( $n < 0.41 ) ?? 0.54 !! ( $n < 0.46 ) ?? 0.58 !! ( $n < 0.51 ) ?? 0.62 !! ( $n < 0.56 ) ?? 0.66 !! ( $n < 0.61 ) ?? 0.70 !! ( $n < 0.66 ) ?? 0.74 !! ( $n < 0.71 ) ?? 0.78 !! ( $n < 0.76 ) ?? 0.82 !! ( $n < 0.81 ) ?? 0.86 !! ( $n < 0.86 ) ?? 0.90 !! ( $n < 0.91 ) ?? 0.94 !! ( $n < 0.96 ) ?? 0.98 !! 1.00 ;
}
while prompt("value: ") -> $value {
last if $value ~~ /exit|quit/; say price_fraction(+$value);
}</lang>
PL/I
<lang PL/I> declare t(20) fixed decimal (3,2) static initial (
.06, .11, .16, .21, .26, .31, .36, .41, .46, .51, .56, .61, .66, .71, .76, .81, .86, .91, .96, 1.01);
declare r(20) fixed decimal (3,2) static initial (
.10, .18, .26, .32, .38, .44, .50, .54, .58, .62, .66, .70, .74, .78, .82, .86, .90, .94, .98, 1);
declare x float, d fixed decimal (3,2); declare i fixed binary;
loop:
do i = 1 to 20; if x < t(i) then do; d = r(i); leave loop; end; end;
</lang>
PicoLisp
<lang PicoLisp>(scl 2)
(de price (Pr)
(format (cdr (rank Pr (quote (0.00 . 0.10) (0.06 . 0.18) (0.11 . 0.26) (0.16 . 0.32) (0.21 . 0.38) (0.26 . 0.44) (0.31 . 0.50) (0.36 . 0.54) (0.41 . 0.58) (0.46 . 0.62) (0.51 . 0.66) (0.56 . 0.70) (0.61 . 0.74) (0.66 . 0.78) (0.71 . 0.82) (0.76 . 0.86) (0.81 . 0.90) (0.86 . 0.94) (0.91 . 0.98) (0.96 . 1.00) ) ) ) *Scl ) )
(for N (0.3793 0.4425 0.0746 0.6918 0.2993 0.5486 0.7848 0.9383 0.2292)
(prinl (price N)) )</lang>
Output:
0.54 0.58 0.18 0.78 0.44 0.66 0.86 0.98 0.38
PureBasic
<lang PureBasic>Procedure.f PriceFraction(price.f)
;returns price unchanged if value is invalid Protected fraction Select price * 100 Case 0 To 5 fraction = 10 Case 06 To 10 fraction = 18 Case 11 To 15 fraction = 26 Case 16 To 20 fraction = 32 Case 21 To 25 fraction = 38 Case 26 To 30 fraction = 44 Case 31 To 35 fraction = 5 Case 36 To 40 fraction = 54 Case 41 To 45 fraction = 58 Case 46 To 50 fraction = 62 Case 51 To 55 fraction = 66 Case 56 To 60 fraction = 7 Case 61 To 65 fraction = 74 Case 66 To 70 fraction = 78 Case 71 To 75 fraction = 82 Case 76 To 80 fraction = 86 Case 81 To 85 fraction = 9 Case 86 To 90 fraction = 94 Case 91 To 95 fraction = 98 Case 96 To 100 fraction = 100 Default ProcedureReturn price EndSelect ProcedureReturn fraction / 100
EndProcedure
If OpenConsole()
Define x.f, i For i = 1 To 10 x = Random(10000)/10000 PrintN(StrF(x, 4) + " -> " + StrF(PriceFraction(x), 2)) Next Print(#CRLF$ + #CRLF$ + "Press ENTER to exit") Input() CloseConsole()
EndIf</lang> Sample output:
0.3793 -> 0.54 0.4425 -> 0.58 0.0746 -> 0.18 0.6918 -> 0.78 0.2993 -> 0.44 0.5486 -> 0.66 0.7848 -> 0.86 0.9383 -> 0.98 0.2292 -> 0.38 0.9560 -> 1.00
Python
Using the bisect standard module to reduce the comparisons with members of the cin array.
<lang python>>>> import bisect >>> _cin = [.06, .11, .16, .21, .26, .31, .36, .41, .46, .51, .56, .61, .66, .71, .76, .81, .86, .91, .96, 1.01] >>> _cout = [.10, .18, .26, .32, .38, .44, .50, .54, .58, .62, .66, .70, .74, .78, .82, .86, .90, .94, .98, 1.00] >>> def pricerounder(pricein): return _cout[ bisect.bisect_right(_cin, pricein) ]</lang>
When dealing with money it is good to think about possible loss of precision. If we change the units to be integer cents we could use the following exact routine: <lang python>>>> import bisect >>> _cin = [ 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76, 81, 86, 91, 96, 101] >>> _cout = [10, 18, 26, 32, 38, 44, 50, 54, 58, 62, 66, 70, 74, 78, 82, 86, 90, 94, 98, 100] >>> def centsrounder(centsin): return _cout[ bisect.bisect_right(_cin, centsin) ]</lang> Other options are to use the fractions or decimals modules for calculating money to a known precision.
Bisection library code
- The
bisect
Python standard library function uses the following code that improves on a simple linear scan through a sorted list: - <lang python>def bisect_right(a, x, lo=0, hi=None):
"""Return the index where to insert item x in list a, assuming a is sorted.
The return value i is such that all e in a[:i] have e <= x, and all e in a[i:] have e > x. So if x already appears in the list, a.insert(x) will insert just after the rightmost x already there.
Optional args lo (default 0) and hi (default len(a)) bound the slice of a to be searched. """
if lo < 0: raise ValueError('lo must be non-negative') if hi is None: hi = len(a) while lo < hi: mid = (lo+hi)//2 if x < a[mid]: hi = mid else: lo = mid+1 return lo</lang>
R
<lang r> price_fraction <- function(x) {
stopifnot(all(x >= 0 & x <= 1)) breaks <- seq(0.06, 1.01, 0.05) values <- c(.1, .18, .26, .32, .38, .44, .5, .54, .58, .62, .66, .7, .74, .78, .82, .86, .9, .94, .98, 1) indices <- sapply(x, function(x) which(x < breaks)[1]) values[indices]
}
- Example usage:
price_fraction(c(0, .01, 0.06, 0.25, 1)) # 0.10 0.10 0.18 0.38 1.00 </lang>
You can extract the contents of the table as follows:
<lang r> dfr <- read.table(tc <- textConnection( ">= 0.00 < 0.06 := 0.10 >= 0.06 < 0.11 := 0.18 >= 0.11 < 0.16 := 0.26 >= 0.16 < 0.21 := 0.32 >= 0.21 < 0.26 := 0.38 >= 0.26 < 0.31 := 0.44 >= 0.31 < 0.36 := 0.50 >= 0.36 < 0.41 := 0.54 >= 0.41 < 0.46 := 0.58 >= 0.46 < 0.51 := 0.62 >= 0.51 < 0.56 := 0.66 >= 0.56 < 0.61 := 0.70 >= 0.61 < 0.66 := 0.74 >= 0.66 < 0.71 := 0.78 >= 0.71 < 0.76 := 0.82 >= 0.76 < 0.81 := 0.86 >= 0.81 < 0.86 := 0.90 >= 0.86 < 0.91 := 0.94 >= 0.91 < 0.96 := 0.98 >= 0.96 < 1.01 := 1.00")); close(tc) breaks <- dfr$V4 values <- dfr$V6 </lang>
Raven
<lang Raven>define getScaleFactor use $v
[ 0.1 0.18 0.26 0.32 0.38 0.44 0.50 0.54 0.58 0.62 0.66 0.70 0.74 0.78 0.82 0.86 0.90 0.94 0.98 1.0 ] as $vals $v 100 * 1 - 5 / 20 min 0 max 1 prefer dup $v "val: %g indx: %d\n" print $vals swap get
0 100 9 range each
100.0 / dup getScaleFactor swap "%.2g -> %.2g\n" print</lang>
- Output:
0 -> 0.1 0.09 -> 0.18 0.18 -> 0.32 0.27 -> 0.44 0.36 -> 0.54 0.45 -> 0.58 0.54 -> 0.66 0.63 -> 0.74 0.72 -> 0.82 0.81 -> 0.9 0.9 -> 0.94 0.99 -> 1
REXX
<lang rexx>/*REXX program to rescale a (decimal fraction) price (0.99 ──► 1.00).*/ pad=' ' /*for inserting spaces into msg. */
do j=0 to 1 by .01; if j==0 then j=0.00 /*special case.*/ say pad 'original price ──►' j pad adjPrice(j) " ◄── adjusted price" end /*j*/
exit /*stick a fork in it, we're done.*/ /*──────────────────────────────────ADJPRICE subroutine─────────────────*/ adjPrice: procedure; parse arg ?
select when ?<0.06 then ?=0.10 when ?<0.11 then ?=0.18 when ?<0.16 then ?=0.26 when ?<0.21 then ?=0.32 when ?<0.26 then ?=0.38 when ?<0.31 then ?=0.44 when ?<0.36 then ?=0.50 when ?<0.41 then ?=0.54 when ?<0.46 then ?=0.58 when ?<0.51 then ?=0.62 when ?<0.56 then ?=0.66 when ?<0.61 then ?=0.70 when ?<0.66 then ?=0.74 when ?<0.71 then ?=0.78 when ?<0.76 then ?=0.82 when ?<0.81 then ?=0.86 when ?<0.86 then ?=0.90 when ?<0.91 then ?=0.94 when ?<0.96 then ?=0.98 when ?<1.01 then ?=1.00 otherwise nop end /*select*/
return ?</lang> output
original price ──► 0.00 0.10 ◄── adjusted price original price ──► 0.01 0.10 ◄── adjusted price original price ──► 0.02 0.10 ◄── adjusted price original price ──► 0.03 0.10 ◄── adjusted price original price ──► 0.04 0.10 ◄── adjusted price original price ──► 0.05 0.10 ◄── adjusted price original price ──► 0.06 0.18 ◄── adjusted price original price ──► 0.07 0.18 ◄── adjusted price original price ──► 0.08 0.18 ◄── adjusted price original price ──► 0.09 0.18 ◄── adjusted price original price ──► 0.10 0.18 ◄── adjusted price original price ──► 0.11 0.26 ◄── adjusted price original price ──► 0.12 0.26 ◄── adjusted price original price ──► 0.13 0.26 ◄── adjusted price original price ──► 0.14 0.26 ◄── adjusted price original price ──► 0.15 0.26 ◄── adjusted price original price ──► 0.16 0.32 ◄── adjusted price original price ──► 0.17 0.32 ◄── adjusted price original price ──► 0.18 0.32 ◄── adjusted price original price ──► 0.19 0.32 ◄── adjusted price original price ──► 0.20 0.32 ◄── adjusted price original price ──► 0.21 0.38 ◄── adjusted price original price ──► 0.22 0.38 ◄── adjusted price original price ──► 0.23 0.38 ◄── adjusted price original price ──► 0.24 0.38 ◄── adjusted price original price ──► 0.25 0.38 ◄── adjusted price original price ──► 0.26 0.44 ◄── adjusted price original price ──► 0.27 0.44 ◄── adjusted price original price ──► 0.28 0.44 ◄── adjusted price original price ──► 0.29 0.44 ◄── adjusted price original price ──► 0.30 0.44 ◄── adjusted price original price ──► 0.31 0.50 ◄── adjusted price original price ──► 0.32 0.50 ◄── adjusted price original price ──► 0.33 0.50 ◄── adjusted price original price ──► 0.34 0.50 ◄── adjusted price original price ──► 0.35 0.50 ◄── adjusted price original price ──► 0.36 0.54 ◄── adjusted price original price ──► 0.37 0.54 ◄── adjusted price original price ──► 0.38 0.54 ◄── adjusted price original price ──► 0.39 0.54 ◄── adjusted price original price ──► 0.40 0.54 ◄── adjusted price original price ──► 0.41 0.58 ◄── adjusted price original price ──► 0.42 0.58 ◄── adjusted price original price ──► 0.43 0.58 ◄── adjusted price original price ──► 0.44 0.58 ◄── adjusted price original price ──► 0.45 0.58 ◄── adjusted price original price ──► 0.46 0.62 ◄── adjusted price original price ──► 0.47 0.62 ◄── adjusted price original price ──► 0.48 0.62 ◄── adjusted price original price ──► 0.49 0.62 ◄── adjusted price original price ──► 0.50 0.62 ◄── adjusted price original price ──► 0.51 0.66 ◄── adjusted price original price ──► 0.52 0.66 ◄── adjusted price original price ──► 0.53 0.66 ◄── adjusted price original price ──► 0.54 0.66 ◄── adjusted price original price ──► 0.55 0.66 ◄── adjusted price original price ──► 0.56 0.70 ◄── adjusted price original price ──► 0.57 0.70 ◄── adjusted price original price ──► 0.58 0.70 ◄── adjusted price original price ──► 0.59 0.70 ◄── adjusted price original price ──► 0.60 0.70 ◄── adjusted price original price ──► 0.61 0.74 ◄── adjusted price original price ──► 0.62 0.74 ◄── adjusted price original price ──► 0.63 0.74 ◄── adjusted price original price ──► 0.64 0.74 ◄── adjusted price original price ──► 0.65 0.74 ◄── adjusted price original price ──► 0.66 0.78 ◄── adjusted price original price ──► 0.67 0.78 ◄── adjusted price original price ──► 0.68 0.78 ◄── adjusted price original price ──► 0.69 0.78 ◄── adjusted price original price ──► 0.70 0.78 ◄── adjusted price original price ──► 0.71 0.82 ◄── adjusted price original price ──► 0.72 0.82 ◄── adjusted price original price ──► 0.73 0.82 ◄── adjusted price original price ──► 0.74 0.82 ◄── adjusted price original price ──► 0.75 0.82 ◄── adjusted price original price ──► 0.76 0.86 ◄── adjusted price original price ──► 0.77 0.86 ◄── adjusted price original price ──► 0.78 0.86 ◄── adjusted price original price ──► 0.79 0.86 ◄── adjusted price original price ──► 0.80 0.86 ◄── adjusted price original price ──► 0.81 0.90 ◄── adjusted price original price ──► 0.82 0.90 ◄── adjusted price original price ──► 0.83 0.90 ◄── adjusted price original price ──► 0.84 0.90 ◄── adjusted price original price ──► 0.85 0.90 ◄── adjusted price original price ──► 0.86 0.94 ◄── adjusted price original price ──► 0.87 0.94 ◄── adjusted price original price ──► 0.88 0.94 ◄── adjusted price original price ──► 0.89 0.94 ◄── adjusted price original price ──► 0.90 0.94 ◄── adjusted price original price ──► 0.91 0.98 ◄── adjusted price original price ──► 0.92 0.98 ◄── adjusted price original price ──► 0.93 0.98 ◄── adjusted price original price ──► 0.94 0.98 ◄── adjusted price original price ──► 0.95 0.98 ◄── adjusted price original price ──► 0.96 1.00 ◄── adjusted price original price ──► 0.97 1.00 ◄── adjusted price original price ──► 0.98 1.00 ◄── adjusted price original price ──► 0.99 1.00 ◄── adjusted price original price ──► 1.00 1.00 ◄── adjusted price
Ruby
A simple function with hardcoded values. <lang ruby>def rescale_price_fraction(value)
raise ArgumentError, "value=#{value}, must have: 0 <= value < 1.01" if value < 0 || value >= 1.01 if value < 0.06 then 0.10 elsif value < 0.11 then 0.18 elsif value < 0.16 then 0.26 elsif value < 0.21 then 0.32 elsif value < 0.26 then 0.38 elsif value < 0.31 then 0.44 elsif value < 0.36 then 0.50 elsif value < 0.41 then 0.54 elsif value < 0.46 then 0.58 elsif value < 0.51 then 0.62 elsif value < 0.56 then 0.66 elsif value < 0.61 then 0.70 elsif value < 0.66 then 0.74 elsif value < 0.71 then 0.78 elsif value < 0.76 then 0.82 elsif value < 0.81 then 0.86 elsif value < 0.86 then 0.90 elsif value < 0.91 then 0.94 elsif value < 0.96 then 0.98 elsif value < 1.01 then 1.00 end
end</lang>
Or, where we can cut and paste the textual table in one place
for the String#lines
method.
For Ruby 1.8.6, use String#each_line
<lang ruby>class Price
ConversionTable = <<-END_OF_TABLE >= 0.00 < 0.06 := 0.10 >= 0.06 < 0.11 := 0.18 >= 0.11 < 0.16 := 0.26 >= 0.16 < 0.21 := 0.32 >= 0.21 < 0.26 := 0.38 >= 0.26 < 0.31 := 0.44 >= 0.31 < 0.36 := 0.50 >= 0.36 < 0.41 := 0.54 >= 0.41 < 0.46 := 0.58 >= 0.46 < 0.51 := 0.62 >= 0.51 < 0.56 := 0.66 >= 0.56 < 0.61 := 0.70 >= 0.61 < 0.66 := 0.74 >= 0.66 < 0.71 := 0.78 >= 0.71 < 0.76 := 0.82 >= 0.76 < 0.81 := 0.86 >= 0.81 < 0.86 := 0.90 >= 0.86 < 0.91 := 0.94 >= 0.91 < 0.96 := 0.98 >= 0.96 < 1.01 := 1.00 END_OF_TABLE
RE = %r{ ([<>=]+) \s* (\d\.\d\d) \s* ([<>=]+) \s* (\d\.\d\d) \D+ (\d\.\d\d) }x
# extract the comparison operators and numbers from the table CONVERSION_TABLE = ConversionTable.lines.inject([]) do |table, line| m = line.match(RE) if not m.nil? and m.length == 6 table << [m[1], m[2].to_f, m[3], m[4].to_f, m[5].to_f] end table end
MIN_COMP, MIN = CONVERSION_TABLE[0][0..1] MAX_COMP, MAX = CONVERSION_TABLE[-1][2..3]
def initialize(value) if (not value.send(MIN_COMP, MIN)) or (not value.send(MAX_COMP, MAX)) raise ArgumentError, "value=#{value}, must have: #{MIN} #{MIN_COMP} value #{MAX_COMP} #{MAX}" end @standard_value = CONVERSION_TABLE.find do |comp1, lower, comp2, upper, standard| value.send(comp1, lower) and value.send(comp2, upper) end.last end attr_reader :standard_value
end</lang>
And a test suite <lang ruby>require 'test/unit'
class PriceFractionTests < Test::Unit::TestCase
@@ok_tests = [ [0.3793, 0.54], [0.4425, 0.58], [0.0746, 0.18], [0.6918, 0.78], [0.2993, 0.44], [0.5486, 0.66], [0.7848, 0.86], [0.9383, 0.98], [0.2292, 0.38], ] @@bad_tests = [1.02, -3]
def test_ok @@ok_tests.each do |val, exp| assert_equal(exp, rescale_price_fraction(val)) assert_equal(exp, Price.new(val).standard_value) end @@bad_tests.each do |val| assert_raise(ArgumentError) {rescale_price_fraction(val)} assert_raise(ArgumentError) {Price.new(val).standard_value} end end
end</lang>
output
Loaded suite price_fraction Started . Finished in 0.001000 seconds. 1 tests, 22 assertions, 0 failures, 0 errors, 0 skips
Run BASIC
<lang runbasic>data .06, .1,.11,.18,.16,.26,.21,.32,.26,.38,.31,.44,.36,.50,.41,.54,.46,.58,.51,.62 data .56,.66,.61,.70,.66,.74,.71,.78,.76,.82,.81,.86,.86,.90,.91,.94,.96,.98
dim od(100) dim nd(100) for i = 1 to 19 read oldDec read newDec j = j + 1 for j = j to oldDec * 100
nd(j) = newDec
next j next i
[loop] input "Gimme a number";numb decm = val(using("##",(numb mod 1) * 100)) print numb;" -->";nd(decm)
goto [loop]</lang>
Gimme a number?12.676 12.676 -->0.78 Gimme a number?4.876 4.876 -->0.94 Gimme a number?34.12 34.12 -->0.26
Scala
<lang scala>def priceFraction(x:Double)=x match {
case n if n>=0 && n<0.06 => 0.10 case n if n<0.11 => 0.18 case n if n<0.36 => ((((n*100).toInt-11)/5)*6+26)/100.toDouble case n if n<0.96 => ((((n*100).toInt-31)/5)*4+50)/100.toDouble case _ => 1.00
}
def testPriceFraction()=
for(n <- 0.00 to (1.00, 0.01)) println("%.2f %.2f".format(n, priceFraction(n)))</lang>
Output
0,00 0,10 0,01 0,10 0,02 0,10 0,03 0,10 0,04 0,10 0,05 0,10 0,06 0,18 ... 0,25 0,38 0,26 0,44 0,27 0,44 0,28 0,44 0,29 0,44 0,30 0,44 0,31 0,50 0,32 0,50 0,33 0,50 0,34 0,50 0,35 0,50 0,36 0,54 0,37 0,54 ... 0,88 0,94 0,89 0,94 0,90 0,94 0,91 0,98 0,92 0,98 0,93 0,98 0,94 0,98 0,95 0,98 0,96 1,00 0,97 1,00 0,98 1,00 0,99 1,00 1,00 1,00
Seed7
<lang seed7>$ include "seed7_05.s7i";
include "float.s7i";
const func float: computePrice (in float: x) is func
result var float: price is 0.0; begin if x >= 0.0 and x < 0.06 then price := 0.10; elsif x < 0.11 then price := 0.18; elsif x < 0.36 then price := flt(((trunc(x * 100.0) - 11) div 5) * 6 + 26) / 100.0; elsif x < 0.96 then price := flt(((trunc(x * 100.0) - 31) div 5) * 4 + 50) / 100.0; else price := 1.0; end if; end func;
const proc: main is func
local var integer: i is 0; begin for i range 0 to 100 do writeln(flt(i) / 100.0 digits 2 <& " " <& computePrice(flt(i) / 100.0) digits 2); end for; end func;</lang>
The following variant of computePrice works with a table and raises RANGE_ERROR when x < 0.0 or x >= 1.01 holds: <lang seed7>const array array float: table is [] (
[] (0.06, 0.10), [] (0.11, 0.18), [] (0.16, 0.26), [] (0.21, 0.32), [] (0.26, 0.38), [] (0.31, 0.44), [] (0.36, 0.50), [] (0.41, 0.54), [] (0.46, 0.58), [] (0.51, 0.62), [] (0.56, 0.66), [] (0.61, 0.70), [] (0.66, 0.74), [] (0.71, 0.78), [] (0.76, 0.82), [] (0.81, 0.86), [] (0.86, 0.90), [] (0.91, 0.94), [] (0.96, 0.98), [] (1.01, 1.00));
const func float: computePrice (in float: x) is func
result var float: price is 0.0; local var integer: index is 1; begin if x >= 0.0 then while x >= table[index][1] do incr(index); end while; price := table[index][2]; else raise RANGE_ERROR; end if; end func;</lang>
Smalltalk
<lang smalltalk>"Table driven rescale" Object subclass: PriceRescale [
|table| PriceRescale class >> new: theTable [ ^ self basicNew initialize: theTable ] initialize: theTable [ table := theTable asOrderedCollection. ^self ] rescale: aPrice [ |v1 v2| 1 to: (table size - 1) do: [:i| v1 := table at: i. v2 := table at: (i+1). ((aPrice >= (v1 x)) & (aPrice < (v2 x))) ifTrue: [ ^ v1 y ] ]. (aPrice < ((v1:=(table first)) x)) ifTrue: [ ^ v1 y ]. (aPrice >= ((v1:=(table last)) x)) ifTrue: [ ^ v1 y ] ]
].
|pr| pr := PriceRescale
new: { 0.00@0.10 . 0.06@0.18 . 0.11@0.26 . 0.16@0.32 . 0.21@0.38 . 0.26@0.44 . 0.31@0.50 . 0.36@0.54 . 0.41@0.58 . 0.46@0.62 . 0.51@0.66 . 0.56@0.70 . 0.61@0.74 . 0.66@0.78 . 0.71@0.82 . 0.76@0.86 . 0.81@0.90 . 0.86@0.94 . 0.91@0.98 . 0.96@1.00 . 1.01@1.00 }.
"get a price" (pr rescale: ( (Random between: 0 and: 100)/100 )) displayNl.</lang>
Tcl
Structured as two functions, one to parse the input data as described in the problem into a form which Tcl can work with easily, and the other to perform the mapping. <lang tcl># Used once to turn the table into a "nice" form proc parseTable table {
set map {} set LINE_RE {^ *>= *([0-9.]+) *< *([0-9.]+) *:= *([0-9.]+) *$} foreach line [split $table \n] {
if {[string trim $line] eq ""} continue if {[regexp $LINE_RE $line -> min max target]} { lappend map $min $max $target } else { error "invalid table format: $line" }
} return $map
}
- How to apply the "nice" table to a particular value
proc priceFraction {map value} {
foreach {minimum maximum target} $map {
if {$value >= $minimum && $value < $maximum} {return $target}
} # Failed to map; return the input return $value
}</lang> How it is used: <lang tcl># Make the mapping set inputTable {
>= 0.00 < 0.06 := 0.10 >= 0.06 < 0.11 := 0.18 >= 0.11 < 0.16 := 0.26 >= 0.16 < 0.21 := 0.32 >= 0.21 < 0.26 := 0.38 >= 0.26 < 0.31 := 0.44 >= 0.31 < 0.36 := 0.50 >= 0.36 < 0.41 := 0.54 >= 0.41 < 0.46 := 0.58 >= 0.46 < 0.51 := 0.62 >= 0.51 < 0.56 := 0.66 >= 0.56 < 0.61 := 0.70 >= 0.61 < 0.66 := 0.74 >= 0.66 < 0.71 := 0.78 >= 0.71 < 0.76 := 0.82 >= 0.76 < 0.81 := 0.86 >= 0.81 < 0.86 := 0.90 >= 0.86 < 0.91 := 0.94 >= 0.91 < 0.96 := 0.98 >= 0.96 < 1.01 := 1.00
} set map [parseTable $inputTable]
- Apply the mapping to some inputs (from the Oz example)
foreach example {.7388727 .8593103 .826687 .3444635 .0491907} {
puts "$example -> [priceFraction $map $example]"
}</lang> Output:
.7388727 -> 0.82 .8593103 -> 0.90 .826687 -> 0.90 .3444635 -> 0.50 .0491907 -> 0.10
Ursala
<lang Ursala>#import flo
le = <0.06,.11,.16,.21,.26,.31,.36,.41,.46,.51,.56,.61,.66,.71,.76,.81,.86,.91,.96,1.01> out = <0.10,.18,.26,.32,.38,.44,.50,.54,.58,.62,.66,.70,.74,.78,.82,.86,.90,.94,.98,1.>
price_fraction = fleq@rlPlX*|rhr\~&p(le,out)</lang> main points:
~&p(le,out)
zips the pair of listsle
andout
into a list of pairs- A function of the form
f\y
applied to an argumentx
evaluates tof(x,y)
- A function of the form
f*|
applied to a pair(x,y)
wherey
is a list, makes a list of pairs withx
on the left of each item and an item ofy
on the right. Then it appliesf
to each pair, makes a list of the right sides of those for whichf
returned true, and makes a separate list of the right sides of those for whichf
returned false. - The suffix
rhr
after the*|
operator extracts the right side of the head of the right list from the result. - The operand to the
*|
operator,fleq@rlPlX
is the less-or-equal predicate on floating point numbers, composed with the function~&rlPlX
which transforms a triple(u,(v,w))
to(v,u)
test program: <lang Ursala>#cast %eL
test = price_fraction* <0.34,0.070145,0.06,0.05,0.50214,0.56,1.,0.99,0.> </lang> output:
< 5.000000e-01, 1.800000e-01, 1.800000e-01, 1.000000e-01, 6.200000e-01, 7.000000e-01, 1.000000e+00, 1.000000e+00, 1.000000e-01>
XPL0
<lang XPL0>include c:\cxpl\codes; \intrinsic 'code' declarations
func real Price(V); \Convert to standard value real V; [V:= V + 0.001; \avoids possible rounding error i.e. 0.059999999 case of
V < 0.06: ret 0.10; V < 0.11: ret 0.18; V < 0.16: ret 0.26; V < 0.21: ret 0.32; V < 0.26: ret 0.38; V < 0.31: ret 0.44; V < 0.36: ret 0.50; V < 0.41: ret 0.54; V < 0.46: ret 0.58; V < 0.51: ret 0.62; V < 0.56: ret 0.66; V < 0.61: ret 0.70; V < 0.66: ret 0.74; V < 0.71: ret 0.78; V < 0.76: ret 0.82; V < 0.81: ret 0.86; V < 0.86: ret 0.90; V < 0.91: ret 0.94; V < 0.96: ret 0.98
other ret 1.00; ];
[Format(1,2); RlOut(0, Price(0.0599)); CrLf(0); RlOut(0, Price(0.10)); CrLf(0); RlOut(0, Price(1.0)); CrLf(0); ]</lang>
Output:
0.18 0.18 1.00
- Programming Tasks
- Financial operations
- Ada
- AutoHotkey
- ALGOL 68
- AWK
- BASIC
- BBC BASIC
- Bracmat
- C
- C sharp
- C++
- Clipper
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- Smalltalk
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- Ursala
- XPL0